U.S. patent application number 14/112503 was filed with the patent office on 2014-03-13 for polyamide-imide solution and polyamide-imide film.
The applicant listed for this patent is Mari Fujii, Masatoshi Hasegawa, Tomonori Iwamoto. Invention is credited to Mari Fujii, Masatoshi Hasegawa, Tomonori Iwamoto.
Application Number | 20140072813 14/112503 |
Document ID | / |
Family ID | 47041668 |
Filed Date | 2014-03-13 |
United States Patent
Application |
20140072813 |
Kind Code |
A1 |
Fujii; Mari ; et
al. |
March 13, 2014 |
POLYAMIDE-IMIDE SOLUTION AND POLYAMIDE-IMIDE FILM
Abstract
An object of the present invention is to obtain a
polyamide-imide solution that has a low linear thermal expansion
coefficient, that is, an excellent linear thermal expansion
coefficient, and that also is excellent in coating applicability. A
further object of the present invention is to provide, with use of
the polyamide-imide solution, a product or member which has high
requirements for heat resistance and a low linear thermal expansion
coefficient. In particular, the present invention is intended to
provide a product or member that is suitably used for applications
in which the polyamide-imide film obtained from the polyamide-imide
solution of the present invention is formed on a surface of an
inorganic material such as metal, metal oxide, or monocrystalline
silicon. The above objects can be achieved by a polyamide-imide
solution including: a specific polyamide-imide; and an organic
solvent, the organic solvent being a mixture solvent of an amide
solvent and a non-amide solvent, the non-amide solvent being at
least one solvent selected from the group consisting of ether
solvents, ketone solvents, ester solvents, glycol ether solvents,
and glycol ester solvents.
Inventors: |
Fujii; Mari; (Shiga, JP)
; Iwamoto; Tomonori; (Shiga, JP) ; Hasegawa;
Masatoshi; (Chiba, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Fujii; Mari
Iwamoto; Tomonori
Hasegawa; Masatoshi |
Shiga
Shiga
Chiba |
|
JP
JP
JP |
|
|
Family ID: |
47041668 |
Appl. No.: |
14/112503 |
Filed: |
April 19, 2012 |
PCT Filed: |
April 19, 2012 |
PCT NO: |
PCT/JP2012/060624 |
371 Date: |
October 17, 2013 |
Current U.S.
Class: |
428/435 ;
252/586; 524/233 |
Current CPC
Class: |
H01L 29/78603 20130101;
C08G 73/14 20130101; Y10T 428/31623 20150401; C08L 79/08 20130101;
H01L 51/0096 20130101; C09D 7/20 20180101; B32B 2379/08 20130101;
B32B 17/064 20130101 |
Class at
Publication: |
428/435 ;
524/233; 252/586 |
International
Class: |
C09D 7/00 20060101
C09D007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 20, 2011 |
JP |
2011-094441 |
Claims
1. A polyamide-imide solution comprising: an organic solvent; and a
polyamide-imide including a structure represented by the general
formula (1): ##STR00011## the organic solvent being a mixture
solvent of an amide solvent and a non-amide solvent, the non-amide
solvent being at least one solvent selected from the group
consisting of ether solvents, ketone solvents, ester solvents,
glycol ether solvents, and glycol ester solvents.
2. The polyamide-imide solution as set forth in claim 1, wherein a
weight ratio of the amide solvent and the non-amide solvent (amide
solvent/non-amide solvent) is in a range of 80/20 to 5/95.
3. The polyamide-imide solution as set forth in claim 1, wherein:
the polyamide-imide including the structure represented by the
general formula (1) is a polyamide-imide represented by the general
formula (6): ##STR00012##
4. The polyamide-imide solution as set forth in claim 1, wherein:
the amide solvent is N,N-dimethylacetamide or
N,N-dimethylformamide; and the non-amide solvent is at least one
solvent selected from the group consisting of methyl ethyl ketone,
methyl isobutyl ketone, cyclohexanone, cyclopentanone,
propyleneglycol monomethylether acetate, methyl triglyme, methyl
tetraglyme, methyl monoglyme, methyl diglyme, ethyl monoglyme,
ethyl diglyme, butyl diglyme, and .gamma.-butyrolactone.
5. A polyamide-imide film comprising a polyamide-imide including a
structure represented by the general formula (1): ##STR00013## the
polyamide-imide film having a birefringence .DELTA.N of 0.040 or
higher, the birefringence being expressed by .DELTA.N=Nxy-Nz, where
Nxy is an in-plane refractive index and Nz is a refractive index in
a thickness direction.
6. A polyamide-imide film obtained by forming a film from a
polyamide-imide solution as set forth in claim 1.
7. The polyamide-imide film as set forth in claim 5, obtained by
forming a film from a polyamide-imide solution, the polyamide-imide
solution including: an organic solvent; and a polyamide-imide
including a structure represented by the general formula (1), the
organic solvent being a mixture solvent of an amide solvent and a
non-amide solvent, the non-amide solvent being at least one solvent
selected from the group consisting of ether solvents, ketone
solvents, ester solvents, glycol ether solvents, and glycol ester
solvents.
8. The polyamide-imide film as set forth in claim 6, obtained by
applying the polyamide-imide solution onto a support.
9. The polyamide-imide film as set forth in claim 5, having a
linear thermal expansion coefficient of 22 ppm/K or less at a
temperature in a range of 100.degree. C. to 300.degree. C.
10. The polyamide-imide film as set forth in claim 5, wherein: the
birefringence .DELTA.N is 0.070 or more and 0.30 or less, the
birefringence .DELTA.N being expressed by .DELTA.N=Nxy-Nz, where
Nxy is an in-plane refractive index and Nz is an refractive
index.
11. A laminate comprising: a polyamide-imide film as set forth in
claim 5; and a glass substrate.
12. A flexible display substrate comprising a polyamide-imide film
as set forth in claim 5.
13. A TFT substrate comprising a polyamide-imide film as set forth
in claim 5.
14. A color filter comprising a polyamide-imide film as set forth
in claim 5.
15. An electronic paper comprising a polyamide-imide film as set
forth in claim 5.
16. An organic EL display comprising a polyamide-imide film as set
forth in claim 5.
17. The polyamide-imide film as set forth in claim 7, obtained by
applying the polyamide-imide solution onto a support.
18. The polyamide-imide film as set forth in claim 6, having a
linear thermal expansion coefficient of 22 ppm/K or less at a
temperature in a range of 100.degree. C. to 300.degree. C.
19. The polyamide-imide film as set forth in claim 6 wherein: the
birefringence .DELTA.N is 0.070 or more and 0.30 or less, the
birefringence .DELTA.N being expressed by .DELTA.N=Nxy-Nz, where
Nxy is an in-plane refractive index and Nz is an refractive index.
Description
TECHNICAL FIELD
[0001] The present invention relates to a polyamide-imide solution
and a polyamide-imide film formed from the polyamide-imide
solution. Further, the present invention relates to a laminate, a
flexible display substrate, a TFT substrate, a color filter, an
electronic paper, and an organic EL each of which includes the
polyamide-imide film.
BACKGROUND ART
[0002] Following recent rapid advancement in electronics including
displays such as a liquid crystal display, an organic EL display,
and an electronic paper, solar cells, and touch panels, demands
have arisen for flexible electronic devices that have a reduced
thickness and a reduced weight. In these electronic devices,
various electronic elements such as a thin film transistor and a
transparent electrode are formed on a glass plate. By replacing
such a glass material by a film material, a reduction in thickness
and weight of a panel itself can be achieved. However, for
formation of such electronic elements, a high-temperature process
is required.
[0003] In a case where the above-described fine elements made from
an inorganic material are formed on a film, a difference in linear
thermal expansion coefficient between the inorganic material and
the film may cause film warping after formation of an inorganic
element or worse, break the inorganic element. Accordingly, there
has arisen a demand for a material that not only has a heat
resistance but also has the same linear expansion coefficient as
the inorganic material.
[0004] Fabrication processes of the electronic devices as described
above are classified into a batch type fabrication process and a
roll-to-roll type fabrication process. When the roll-to-roll
fabrication process is employed, new production equipment is
required and it also becomes necessary to overcome several problems
caused by reeling in or a contact between films. Meanwhile, the
batch type fabrication process is a process in which (i) a coating
resin solution is applied onto a substrate such as a glass
substrate or metal substrate, and then dried so that a substrate is
formed, and (ii) subsequently, thus applied and dried coating resin
solution is peeled off. Therefore, the batch type fabrication
process is superior in terms of cost because processes and
equipment for current glass substrates such as a TFT glass
substrate can be used.
[0005] In view of a background as described above, it has been
strongly demanded to develop a coating resin solution (i) that
makes it possible to obtain a coating film with both heat
resistance and a high dimensional stability and (ii) that also
allows use of an existing batch type fabrication process in
production of such a coating film.
[0006] As a material that satisfies such a demand, polyimide has
been studied. Polyimide resin is excellent in heat resistance,
mechanical strength, electric characteristics, and the like.
Accordingly, the polyimide resin has conventionally been used
widely as an industrial material in an electric field, an
electronic field, a mechanical field, an aeronautical field, and
the like fields. Unlike general polyimides, in particular, many
known polyamide-imides are soluble in an organic solvent (see, for
example, Patent Literature 1). Such polyamide-imides have suitably
been used in applications, such as enamel varnish, a coating agent
for electric insulation, and a painting material, where film
formation with solution is essential.
[0007] Meanwhile, an amide solvent is often used as a solvent for
use in dissolution of polyimide. The amide solvent has a high
solubility; however, the amino solvent also has a high polarity and
accordingly, easily absorbs moisture. Therefore, in an application
process, the amide solvent tends to absorb moisture in the air and
cause phase separation. This often causes a problem of whitening of
a coating film surface. Particularly, in the case of the batch type
fabrication process, it is predictable that a waiting time occurs
after the application process and before a step following the
application process. This means that there is a high possibility
that the problem of the whitening occurs in the case of the batch
type fabrication process. The whitening causes a concern over
deterioration or the like of a surface nature and a problem that
may consequently arise in a subsequent processing step. In order to
solve this problem, development of a polyimide exhibiting
solubility in a non-amide solvent has been discussed (Patent
Literature 2). Further, Patent Literature 3 discloses a polyimide
containing an amide group.
CITATION LIST
Patent Literatures
[0008] [Patent Literature 1] [0009] Japanese Patent Application
Publication, Tokukaihei, No. 5-59174 A (published on Mar. 9, 1993)
[0010] [Patent Literature 2] [0011] Japanese Patent Application
Publication, Tokukai, No. 2006-2163 A (published on Jan. 5, 2006)
[0012] [Patent Literature 3] [0013] Japanese Patent Application
Publication, Tokukai, No. 2010-106225 A (May 13, 2010)
SUMMARY OF INVENTION
Technical Problem
[0014] There are many known soluble polyimides. However, it is
known that a polyamide-imide disclosed in Patent Literature 1 does
not exhibit a low linear thermal expansion characteristic because
the polyamide-imide contains an aliphatic group having a low
rigidity. Meanwhile, the polyimide disclosed in Patent Literature 2
is soluble in a ketone solvent or ether solvent and can be applied
without causing a whitening phenomenon. However, this polyimide
includes a flexible component in a polymer skeleton and
consequently, rigidity of a polymer main chain is lost. Therefore,
it is difficult that this polyimide has both heat resistance and a
high dimensional stability.
[0015] Patent Literature 3 synthesizes a polyamide-imide, as a
soluble polyamide-imide, from diamine and tetracarboxylic
dianhydride containing an amide group, by first synthesizing the
tetracarboxylic dianhydride. However, Patent Literature 3 does not
touch anything about a relation between a polyamide-imide solution
and a linear thermal expansion coefficient. Further, Patent
Literature 3 does not disclose a sufficient thermal expansion
characteristic for a case where the polyamide-imide solution is
applied on a base material that is made of an inorganic material.
Furthermore, Patent Literature 3 does not touch anything about a
solvent in preparation of a polyamide solution and coating
applicability (capability of being applied to coating) of the
polyamide solution.
[0016] As described above, a soluble polyamide-imide has been
conventionally known. However, the polyamide-imide solution that
has been disclosed so far is not a polyamide-imide solution (i)
that makes it possible to form a film that has a very low linear
thermal expansion coefficient and (ii) that can be applied without
whitening in an application process of the polyamide-imide
solution. The present invention is attained in view of the above
circumstances. An object of the present invention is to obtain a
polyamide-imide solution that has a low linear thermal expansion
coefficient, that is, an excellent thermal expansion coefficient,
and that also is excellent in coating applicability. A further
object of the present invention is to provide, with use of the
polyamide-imide solution, a product or member which has high
requirements for heat resistance and a low linear thermal expansion
coefficient. In particular, the present invention is intended to
provide a product or member that is suitably used for applications
in which the polyamide-imide film obtained from the polyamide-imide
solution of the present invention is formed on a surface of an
inorganic material such as glass, metal, metal oxide, or
monocrystalline silicon.
Solution to Problem
[0017] The inventors of the present invention found that use of a
mixture solvent of an amide solvent and a non-amide solvent is very
effective in achieving the above object of the present invention,
that is, in obtaining a polyamide-imide solution that has an
excellent solubility in an organic solvent, a low linear thermal
expansion characteristic, that is, an excellent linear thermal
expansion characteristic, and also an excellent coating
applicability (i.e., a polyamide-imide solution (i) that includes a
polyamide-imide having an excellent solubility in an organic
solution and a low linear expansion characteristic, that is, an
excellent linear expansion characteristic and (ii) that is
excellent in coating applicability).
[0018] In order to solve the above problem, a polyamide-imide
solution of the present invention includes: an organic solvent; and
a polyamide-imide including a structure represented by the general
formula (1) below, the organic solvent being a mixture solvent of
an amide solvent and a non-amide solvent, the non-amide solvent
being at least one solvent selected from the group consisting of
ether solvents, ketone solvents, ester solvents, glycol ether
solvents, and glycol ester solvents.
##STR00001##
[0019] In order to solve the above problem, a polyamide-imide film
of the present invention includes a polyamide-imide including a
structure represented by the following general formula (1)
below:
##STR00002##
[0020] the polyamide-imide film having a birefringence .DELTA.N of
0.040 or higher, the birefringence being expressed by
.DELTA.N=Nxy-Nz, where an in-plane refractive index is Nxy and a
refractive index in a thickness direction is Nz.
Advantageous Effects of Invention
[0021] The polyamide-imide solution of the present invention does
not whiten in an application process, but shows an excellent
coating applicability. Further, a polyamide-imide film obtained
from the polyamide-imide solution has a very low linear thermal
expansion coefficient.
DESCRIPTION OF EMBODIMENTS
[0022] The following discusses the present invention in detail.
Note that, however, the present invention is by no means limited to
the description below, but various modifications can be made within
the scope described below. Further, all Patent Literatures cited in
the present Specification is incorporated herein by reference. In
addition, note that "A to B" indicative of a numerical range means
"A or more and B or less" in the present Specification unless
specifically noted otherwise.
[0023] The present invention relates to a polyamide-imide solution
includes: an organic solvent; and a polyamide-imide including a
structure represented by the general formula (1) below, the organic
solvent being a mixture solvent of an amide solvent and a non-amide
solvent, the non-amide solvent being at least one solvent selected
from the group consisting of ether solvents, ketone solvents, ester
solvents, glycol ether solvents, and glycol ester solvents.
[0024] The present invention relates to a polyamide-imide solution
more preferably includes: an organic solvent; and a polyamide-imide
represented by the general formula (1), the organic solvent being a
mixture solvent of an amide solvent and a non-amide solvent, the
non-amide solvent being at least one solvent selected from the
group consisting of ether solvents, ketone solvents, ester
solvents, glycol ether solvents, and glycol ester solvents.
[0025] First, the following discusses a polyamide-imide including a
structure represented by the following general formula (1).
##STR00003##
[0026] In view of obtaining both a low linear thermal expansion
coefficient and solution processability/coating applicability, it
is preferable to use a polyamide-imide including a structure
represented by the following formula (6) among polyamide-imides
including the structure represented by the above general formula
(1).
##STR00004##
[0027] Further, the polyamide-imide including the structure
represented by the above general formula (1) is more preferably a
polyamide-imide represented by the general formula (1). In view of
obtaining both a low linear thermal expansion coefficient and
solution processability/coating applicability, it is more
preferable to use a polyamide-imide represented by the formula (6)
among polyamide-imides represented by the above general formula
(1).
[0028] As a method for producing a polyamide-imide of the present
invention is not specifically limited but a production method
appropriate for achieving the object can be selected. For example,
the method for producing the polyamide-imide of the present
invention may be (A) a method (one-pot method) including the steps
of (i) reacting trimellitic anhydride chloride with diamine
represented by the following formula (2) or (3) in the presence of
a solvent and (ii) imidizing, in a solution obtained in the step
(i), tetracarboxylic dianhydride represented by the following
formula (4), the tetracarboxylic dianhydride having never been
isolated, or alternatively (B) a method including the steps of (i)
reacting trimellitic anhydride chloride with diamine represented by
the following formula (2) or (3), (ii) isolating and purifying
tetracarboxylic dianhydride represented by the following formula
(4), and (iii) imidizing thus once isolated and purified
tetracarboxylic dianhydride by reacting the tetracarboxylic
dianhydride with diamine. As to the method for isolating the
tetracarboxylic dianhydride represented by the following formula
(4) and then reacting this tetracarboxylic dianhydride with
diamine, it is possible to employ a method as described in Japanese
Patent Application Publication, Tokukai, No. 2010-106225 or the
like. For example, Synthesis Example 2 described later employs the
method for producing a polyamide-imide as described in Japanese
Patent Application Publication, Tokukai, No. 2010-106225. Further,
if necessary, an accelerant such as acetic acid or tertiary amine
may be used.
##STR00005##
[0029] In synthesis of the polyamide-imide according to the one-pot
method, a polyamide-amide acid represented by the following general
formula (5) is first synthesized as a precursor of the
polyamide-imide.
##STR00006##
[0030] This synthesis of the polyamide-amide acid can be carried
out by mixing a diamine component and trimellitic anhydride
chloride. It is preferable that the diamine component and
trimellitic anhydride chloride are mixed under stirring. A stirring
time here is preferably 1 to 24 hours. As to a reaction temperature
at stirring, an optimum temperature is selected as appropriate
depending on a material in use. More specifically, the reaction
temperature is preferably in a range of -10.degree. C. to
50.degree. C., and more preferably in a range of 0.degree. C. to
30.degree. C. Because a synthesis reaction of the polyamide-amide
acid is a polycondensation reaction, a molecular weight can be
adjusted by changing a ratio of the diamine component and
trimellitic anhydride chloride that are to be mixed. The ratio can
be selected as appropriate in accordance with a target molecular
weight. In view of obtaining (i) solubility in an organic solvent
and (ii) a low linear thermal expansion characteristic of a
resultant polyamide-imide, the ratio is preferably in a range of
90:100 to 110:100. As to a method for mixing the diamine component
and trimellitic anhydride chloride, it is possible to employ a
method in which the above acid anhydride chloride is added to the
diamine component or a method in which the diamine component is
added to the above anhydride chloride. The method in which
trimellitic anhydride chloride is added to the diamine component is
more preferable. Moreover, an entire amount of trimellitic
anhydride chloride or the diamine component may be added at a time,
or the amount of trimellitic anhydride chloride or the diamine
component may be added separately in parts so that the entire
amount of trimellitic anhydride chloride or the diamine component
is made up in total.
[0031] In the one-pot method, the organic solvent used in
polymerization of the polyamide-amide acid is not specifically
limited, as long as the solvent reacts with neither trimellitic
anhydride chloride nor diamine for use in the polymerization and
the polyamide-amide acid as a precursor can be dissolved in the
solvent. Examples of such a solvent are: urea solvents such as
methylurea and N,N-dimethylethylurea; sulfoxide solvents or sulfone
solvents such as dimethylsulfoxide, diphenylsulfone, and
tetramethylsulfone; amide solvents such as N,N-dimethylacetamide
(hereinafter, also referred to as DMAC), N,N'-diethylacetamide,
N-methyl-2-pyrolidone (hereinafter, also referred to as NMP),
.gamma.-butyrolactone (hereinafter, also referred to as GBL), and
hexamethylphosphoric triamide; alkyl halide solvents such as
chloroform and methylene chloride; aromatic hydrocarbon solvents
such as benzene and toluene; and ether solvents such as
tetrahydrofuran, 1,3-dioxolan, 1,4-dioxane, dimethyl ether, diethyl
ether, and p-crezolmethylether. In general, these solvents may be
used solely or according to need, two or more of the solvents may
be used in combination. In view of solubility of the
polyamide-amide acid and polymerization reactivity, DMAC, NMP, or
the like is more preferably used.
[0032] As to a possible method for converting the polyamide-amide
acid as a precursor of the polyamide-imide, there is a method in
which the polyamide-amide acid is imidized by adding a dehydration
catalyst and an imidizing agent to a polyamide-amide acid solution.
Thus obtained solution containing the polyamide-imide, the
dehydration catalyst, and the imidizing agent can be used as a
polyamide-imide solution. Further, by introducing a poor solvent
into thus obtained solution containing the polyamide-imide, the
dehydration catalyst, and the imidizing agent, the polyamide-imide
in a solid state can be precipitated. It is particularly preferable
to employ a method in which the polyamide-imide in a solid state is
once isolated. This is because according to such a method, (i) with
the poor solvent, it is possible to wash and remove the dehydration
catalyst, the imidizing agent, and an impurity (hydrochloride) that
has been produced in synthesis of the precursor and (ii) any of
various kinds of organic solvents can be selected in accordance
with a substrate (also called a "support" in the present
specification) that is to be coated.
[0033] The imidizing agent can be a tertiary amine. The tertiary
amine is preferably a heterocyclic tertiary amine. Concrete
preferred examples of such a heterocyclic tertiary amine are
pyridine, picoline, quinoline, and isoquinoline. As the dehydration
catalyst, acid anhydride is used. More specifically, preferred
concrete examples of the acid anhydride are acetic anhydride,
propionic anhydride, n-butyric anhydride, benzoic anhydride, and
trifluoroacetic anhydride.
[0034] An amount of the imidizing agent to be added is 0.5 to 5.0
molar equivalent, more preferably 0.7 to 2.5 molar equivalent, and
most preferably 0.8 to 2.0 molar equivalent with respect to an
amide group produced by a reaction between an acid anhydride group
and an amino group. Meanwhile, an amount of the dehydration
catalyst to be added is 0.5 to 10.0 molar equivalent, more
preferably 0.7 to 5.0 molar equivalent and most preferably 0.8 to
3.0 with respect to the amide group produced by the reaction
between the acid anhydride group and the amino group.
[0035] When the imidizing agent and the dehydration catalyst are
added to the polyamide-amide acid solution, the imidizing agent and
the dehydration catalyst that have not been dissolved in a solvent
can be directly added or alternatively, the imidizing agent and the
dehydration catalyst that have been dissolved in a solvent can be
added. According to a method in which the imidizing agent and the
dehydration catalyst are directly added, before the imidizing agent
and the dehydration catalyst are uniformly dispersed in a solution,
imidization reaction may rapidly proceed locally and as a result, a
gel may be produced. Accordingly, more preferably, the imidizing
agent and the dehydration catalyst are first dissolved in a solvent
so as to be moderately diluted and then thus obtained solution is
mixed in the polyamide-amide acid solution.
[0036] In a case where, as described above, the polyamide-imide is
to be obtained as a solid substance by (i) adding a dehydration
catalyst and a imidizing agent to the polyamide-amide acid, (ii)
completing imidization within a solution and (iii) then introducing
a poor solvent into the solution, the following methods can be
employed: (a) a method in which the polyamide-imide in a solid
state is isolated by introducing, into a poor solvent, the
polyamide-imide solution containing the polyamide-imide, the
imidizing agent and the dehydration catalyst; or (b) a method in
which the polyamide-imide in a solid state is precipitated by
introducing a poor solvent into the polyamide-imide solution
containing the polyamide-imide, the imidizing agent and the
dehydration catalyst. The polyamide-imide in a solid state includes
various forms, such as a powder form and a flake form, of
polyamide-imide. An average particle diameter of such solid-state
polyamide-imide is preferably in a range of 5 mm or less, more
preferably in a range of 3 mm or less, and most preferably in a
range of 1 mm or less.
[0037] The poor solvent of the polyamide-imide in the present
invention can be any solvent that can be mixed with the organic
solvent that is used as a solvent for dissolving the
polyamide-imide. Examples of such a poor solvent for
polyamide-imide are: water, methyl alcohol, ethyl alcohol, 2-propyl
alcohol (isopropyl alcohol), ethylene glycol, triethylene glycol,
2-butyl alcohol, 2-hexyl alcohol, cyclopentyl alcohol, cyclohexyl
alcohol, phenol, and t-butyl alcohol. Among the above alcohols,
alcohols such as 2-propyl alcohol (isopropyl alcohol), 2-butyl
alcohol, 2-pentyl alcohol, phenol, cyclopentyl alcohol, cyclohexyl
alcohol, and t-butyl alcohol are preferable because these alcohols
do not deteriorate stability and an imidization ratio of the
polyamide-imide in a solid state after isolation; and 2-propyl
alcohol is particularly preferable.
[0038] When the poor solvent is introduced into the polyamide-imide
solution, a solid content concentration of the polyamide-imide
solution is not specifically limited as long as the polyamide-imide
solution has a viscosity that allows stirring. However, in view of
reducing a particle diameter of the polyamide-imide in a solid
state, a lower solid content concentration of the polyamide-imide
solution, that is, a dilute polyamide-imide solution is more
preferable. Accordingly, the poor solvent is preferably introduced
into the polyamide-imide solution after the polyamide-imide
solution is diluted so as to have the solid content concentration
of 15% or less, and more preferably, 10% or less. Further, it is
preferable that the solid content concentration of the
polyamide-imide solution be 5% or higher, because an amount of the
poor solvent used for precipitation of the polyamide-imide does not
become too large at such a solid content concentration. The amount
of the poor solvent used for precipitation is preferably equal to
or more than an amount of the polyamide-imide solution, and more
preferably twice to three times as much as the amount of the
polyamide-imide solution. Here, the solid content indicates all
components except solvent and the solid content concentration
indicates a percent concentration by weight of the solid content in
an entire solution.
[0039] The polyamide-imide obtained here in a solid state contains
a small amount of the imidizing agent and the dehydration catalyst.
Therefore, this polyamide-imide is preferably washed several times
with the poor solvent, in particular, with an alcohol solvent such
as 2-propyl alcohol.
[0040] A drying method for thus obtained polyamide-imide in a solid
state may be either vacuum drying or hot-air drying. For the
purpose of completely removing the solvent contained in the
polyamide-imide in a solid state, vacuum drying is desirable. A
drying temperature is preferably in a range of 100.degree. C. to
200.degree. C. and particularly preferably in a range of
120.degree. C. to 180.degree. C.
[0041] Further, the polyamide-imide including the structure
represented by the above general formula (1) may be produced by (i)
first applying the polyamide-amide acid solution as a precursor of
the polyamide-imide onto a support and (ii) then subjecting the
polyamide-amide acid solution on the support to heat
imidization.
[0042] Though a preferable weight-average molecular weight of the
polyamide-imide of the present invention depends on an application
of the polyamide-imide, the weight-average molecular weight is
preferably in a range of 5,000 to 500,000, more preferably in a
range of 10,000 to 300,000, and most preferably in a range of
30,000 to 200,000. When the weight-average molecular weight of the
polyamide-imide is less than 5,000, a coating film or film made of
such a polyamide-imide may not be able to have a satisfactory
characteristic because, for example, such a coating film or film
becomes very weak. Meanwhile, when the weight-average molecular
weight of the polyamide-imide is more than 500,000, a solution
viscosity increases. This may result in deterioration in
handleability or deterioration in solubility. Consequently, it may
not be possible to obtain a coating film or film whose surface is
smooth and whose film thickness is even. In other words, when the
weight-average molecular weight of the polyamide-imide is 5,000 or
more, a coating film or film having a sufficient strength can be
easily obtained from such a polyamide-imide. Meanwhile, when the
weight-average molecular weight of the polyamide-imide is 500,000
or less, solubility can be ensured. Therefore, a coating film or
film whose surface is smooth and whose film thickness is even can
be easily obtained from the polyamide-imide having such a
weight-average molecular weight. The molecular weight here
indicates a value based on polyethylene glycol measured by gel
permeation chromatography (GPC).
[0043] Next, the following discusses the polyamide-imide solution
of the present invention. The polyamide-imide produced by the
above-described method is soluble in an appropriate solvent that
exhibits solubility for the polyamide-imide. Generally, in many
cases, an amide solvent is used as a solvent for dissolving the
polyamide-imide. The amide solvent here means an organic solvent
containing an amide group. Though the amide solvent is excellent in
solubility, the amide solvent has a high moisture absorbency.
Accordingly, in view of whitening of a coating film (hereinafter,
also referred to as a wet film), such an amide solvent is not
preferable. This is because in the case of a batch type fabrication
process, it is predictable that in an application process of the
polyamide-imide solution, a waiting time occurs before a following
step starts. Meanwhile, many non-amide solvents exhibit a
hydrophobic characteristic. Therefore, though such a non-amide
solvent is inferior in solubility to an amide solvent, the
non-amide solvent is effective in suppressing whitening of a wet
film in an application process of the polyamide-imide solution. The
non-amide solvent here means a solvent having a higher hydrophobic
characteristic as compared to the amino solvent and more
specifically, indicates a group of solvents including ether
solvents, ketone solvents, ester solvents, glycol ether solvents,
and glycol ester solvents. However, each solvent in the group of
non-amide solvents generally has a low solubility for the
polyamide-imide. Therefore, it is difficult that these solvents are
solely used. Further, the non-amide solvent often has a low boiling
point in general and such a non-amide solvent easily evaporates at
a normal temperature in an application process. This may cause a
change in viscosity of the polyamide-imide solution. This may also
cause drying of the polyamide-imide solution on a die lip in the
application process and consequently result in short-lasting
application processability during application process. Further, in
consideration of handleability in production, the organic solvent
to be used preferably has less odor.
[0044] Accordingly, in the present invention, it was found that use
of (i) an amide solvent exhibiting a high solubility for the
polyamide-imide and (ii) a non-amide solvent in combination makes
it possible to ensure a solubility, to obtain an excellent
long-lasting application processability during application process,
and further to suppress whitening caused by moisture absorption in
an application process. The solvent used in the polyamide-imide
solution of the present invention is a mixture solvent of an amide
solvent and a non-amide solvent. The non-amide solvent is at least
one solvent selected from the group consisting of ether solvents,
ketone solvents, ester solvents, glycol ether solvents and glycol
ester solvents. As the amide solvent, in view of solubility, it is
preferable, to use N,N-dimethylacetamide or N,N-dimethylformamide
(hereinafter, also referred to as DMF). The non-amide solvent is
preferably a solvent selected from methyl ethyl ketone, methyl
isobutyl ketone, cyclohexanone, cyclopentanone, propyleneglycol
monomethylether acetate, methyl triglyme, methyl tetraglyme, methyl
monoglyme, methyl diglyme, ethyl monoglyme, ethyl diglyme, butyl
diglyme, and .gamma.-butyrolactone. It is particularly preferable
to use a solvent selected from cyclohexanone, cyclopentanone,
propyleneglycol monomethylether acetate, and methyl triglyme, in
view of the fact that these solvents each have a boiling point that
does not largely differ from a boiling point of an amide solvent.
Further, in view of improvement in whitening and less odor, it is
preferable to use a symmetrical glycol diether solvent (glyme
solvent) such as methyl triglyme, methyl tetraglyme, methyl
monoglyme, methyl diglyme, ethyl monoglyme, ethyl diglyme, and
butyl diglyme. Among these solvents, methyl triglyme is
particularly preferable, in view of a smaller difference in boiling
point from an amide solvent and in view of solubility for the
polyamide-imide.
[0045] A mixture ratio of the amide solvent and the
non-amide-solvent can be selected as appropriate within a range
where transparency and uniformity of the polyamide-imide solution
are maintained and whitening is suppressed. The mixture weight
ratio, that is, a weight ratio (amide-solvent/non-amide solvent) of
the amide solvent and the non-amide solvent is preferably in a
range of 80/20 to 5/95, more preferably in a range of 80/20 to
10/90, much more preferably in a range of 70/30 to 20/80, and
particularly preferably in a range of 70/30 to 30/70.
[0046] The viscosity of the polyamide-imide solution is selected as
needed in accordance with a coating thickness and a coating
environment and the viscosity is not specifically limited. The
viscosity is preferably in a range of 0.1 Pas to 50 Pas, and more
preferably in a range of 0.5 Pas to 30 Pas. In a case where the
viscosity is less than 0.1 Pas, the viscosity of the solution is
too low to ensure a sufficient preciseness in film thickness. On
the other hand, in a case where the viscosity is more than 50 Pas,
the viscosity of the solution is too high to ensure preciseness in
film thickness. Moreover, such a high viscosity of more than 50 Pas
may produce a portion that dries immediately after application of
the solution and may result in a defect in appearance such as a
defect caused by gel formation. In other words, a polyamide-imide
solution viscosity of 0.1 Pas or more is preferable because a
sufficient preciseness in film thickness can be ensured. Further, a
polyamide-imide solution viscosity of 50 Pas or less is preferable
because preciseness in film thickness can be ensured. Further, such
a viscosity of 50 Pas or less suppresses the occurrence of a
portion that dries immediately after application of the solution
and as a result, a consequent defect in appearance such as gel
deformity does not occur easily.
[0047] For example, in the polyamide-imide solution, a content of
the polyamide-imide represented by the above general formula (1) is
preferably in a range of 1% by weight to 50% by weight and more
preferably, in a range of 7% by weight to 20% by weight. When the
content is less than 1% by weight, it is difficult to stably obtain
a uniform film. On the other hand, when the content is more than
50% by weight, the possibility of the occurrence of a problem in
storage stability and/or the possibility of formation of a
non-uniform film increases. Therefore, such a content in a range of
less than 1% by weight or more than 50% by weight is not
preferable. In other words, in the polyamide-imide solution, a
content of the polyamide-imide is preferably in a range of 1% by
weight or more and 50% by weight or less. When the content of the
polyamide-imide presented by the above formula (1) is 1% by weight
or more, an even film can be easily obtained. Meanwhile, when the
content is 50% by weight or less, the possibility of the occurrence
of a problem in storage stability and/or the possibility of
formation of an uneven film becomes low.
[0048] Next, the following discusses the polyamide-imide film of
the present invention. The polyamide-imide film of the present
invention is a formed film containing a polyamide-imide including a
structure represented by the above general formula (1). The
polyamide-imide film of the present invention has a birefringence
.DELTA.N of 0.040 or higher, the birefringence being expressed by
.DELTA.N=Nxy-Nz, where an in-plane refractive index is Nxy and a
refractive index in a thickness direction is Nz.
[0049] The film thickness of the polyamide-imide film of the
present invention is preferably in a range of 5 .mu.m to 100 .mu.m,
and more preferably in a range of 10 .mu.m to 50 .mu.m, in view of
a sufficient film strength and easy handling. Further, because the
film thickness affects the linear thermal expansion coefficient,
the film thickness of the polyamide-imide film of the present
invention is most preferably in a range of 15 .mu.m to 40 .mu.m in
view of fulfilling both film strength and a low thermal expansion
characteristic.
[0050] The following discusses a method for producing the
polyamide-imide film of the present invention. The polyamide-imide
film of the present invention can be obtained by forming a film
from the polyamide-imide solution prepared by the above-described
method. More specifically, the polyamide-imide film of the present
invention is obtained by applying, onto a support, the
polyamide-imide solution prepared by the above-described method.
After this application of the polyamide-imide solution, a film is
formed by drying and thereby, the polyamide-imide film can be
obtained. By using the polyamide-imide solution of the present
invention for film formation, self-alignment of polymer chains is
induced. This develops a low linear thermal expansion
characteristic. As to a drying temperature in film formation, any
condition can be selected in accordance with a process. The drying
temperature is not specifically limited.
[0051] The polyamide-imide film obtained by the above production
method has, as film characteristics, a low linear thermal expansion
characteristic and a dimensional stability before and after
heating. For example, in a case where values of a linear thermal
expansion characteristic and a dimensional stability are to be
measured by a thermal mechanical analysis (TMA), a film thickness
is measured and a film is cut into a film sample having a size of
10 mm.times.3 mm. Then, while a load of 3.0 g is being applied to
this film sample, the values are measured at a temperature increase
rate of 10.degree. C./min. At this time, it is possible to obtain a
polyamide-imide film whose linear thermal expansion coefficient at
a temperature in a range of 100.degree. C. to 300.degree. C. is 22
ppm/K or less, more preferably 20 ppm/K or less, and much more
preferably 15 ppm/K or less, and particularly preferably 13 ppm/K
or less. The linear thermal expansion coefficient in the range of
100.degree. C. to 300.degree. C. is a value obtained by an
evaluation method as described in "(3)
[0052] Linear thermal Expansion Coefficient of Film (Polyamide
Film)".
[0053] Further, the polyamide-imide film of the present invention
has a value of the birefringence .DELTA.N of 0.040 or more, the
birefringence .DELTA.N being expressed by an expression:
.DELTA.N=Nxy-Nz,
where: an in-plane refractive index of the polyimide film is Nxy;
and a refractive index of the polyamide-imide film in a thickness
direction is Nz. Such a value of the birefringence .DELTA.N is more
preferably in a range of 0.070 or more and 0.30 or less, much more
preferably in a range of 0.075 or more and 0.30 or less,
particularly preferably in a range of 0.085 or more and 0.30 or
less, and the most preferably, in a range of 0.085 or more and 0.20
or less. In a case where the value of the birefringence .DELTA.N is
less than 0.040, in-plane molecular orientation becomes
insufficient and the linear thermal expansion coefficient becomes
higher. Therefore, such a birefringence .DELTA.N of less than 0.040
is not preferable. On the other hand, in a case were the value of
the birefringence .DELTA.N is more than 0.30, crystallization of
the film occurs. This may result in a cloudy film. Therefore, such
a birefringence .DELTA.N of more than 0.30 is not preferable. In
other words, in a case where the value of the birefringence
.DELTA.N is 0.040 or more, in-plane molecular orientation becomes
sufficiently high and the linear thermal expansion coefficient
becomes low. Therefore, the birefringence .DELTA.N of 0.040 or more
is preferable. In addition, in a case where the value of the
birefringence .DELTA.N is 0.30 or less, film crystallization does
not easily occur and accordingly, the film does not easily become
cloudy. Therefore, the birefringence .DELTA.N of 0.30 or less is
preferable.
[0054] When the polyamide-imide film is to be formed, the
polyamide-imide solution is applied to a support. Examples of such
a support used for formation of the polyamide-imide film are, for
example: a glass substrate; a metal substrate or metal belt made
of, for example, SUS; or a film made of a plastic selected from
among polyethylene terephthalate, polycarbonate, polyacrylate,
polyethylene naphthalate, triacetyl cellulose, and the like.
However, the support is not limited to the above-described
examples. In a case where a plastic film is used as the support, it
is necessary to select as appropriate a plastic film made of a
material that does not dissolve in the organic solvent used for
dissolving the polyamide-imide.
[0055] It is preferable that the polyamide-imide film of the
present invention has a glass transition temperature as high as
possible, in view of heat resistance. The glass transition
temperature is preferably 250.degree. C. or higher at the time when
measurement is carried out by differential scanning calorimetry
(DSC) or dynamic mechanical analysis (DMA). The glass transition
temperature of 300.degree. C. or higher is more preferable because
a higher heat processing temperature can be used.
[0056] The polyamide-imide of the present invention can be directly
provided for a coating or formation process for producing a product
or a component member. It is also possible to subject the
polyamide-imide of the present invention formed into a film to
processing such as coating so that a laminate is obtained. For
providing the polyamide-imide of the present invention for a
coating or formation process, it is possible to mix a photo-curable
or thermosetting component, non-polymerizable binder resin other
than the polyamide-imide of the present invention, and/or other
component in production of the polyamide-imide solution of the
present invention. Further, if necessary, it is possible to use the
polyamide-imide of the present invention dissolved or dispersed in
a solvent.
[0057] In order to give processing characteristics or various types
of functionality to the polyamide-imide film of the present
invention, it is also possible to mix any of other various organic
or inorganic low-molecular compounds or other various organic or
inorganic high-molecular compounds. For example, it is possible to
mix a colorant, a surfactant, a leveling agent, a plasticizer, fine
particles, a sensitizer, and/or the like. The fine particles
encompass organic fine particles made of, for example, polystyrene
and polytetrafluoroethylene and inorganic fine particles made of,
for example, colloidal silica, carbon, or phyllosilicate, and the
like. These fine particles may be porous or may have a hollow
structure. Further, a function or a form of such a compound may be
pigment, filler, fiber or the like.
[0058] The polyamide-imide solution and polyamide-imide film of the
present invention each generally contains in general, 5.00% to
99.9% by weight of a solid content of the polyamide-imide including
the structure represented by the general formula (1). Note that the
expression "99.9% by weight" means "substantially all". The solid
content here indicates a substance obtained in a state where a
content of a residual solvent is 0.1% by weight or less as a result
of drying a solvent from a whole, that is, each of the
polyamide-imide solution and the polyamide-imide film. A mixture
ratio of an optional component is preferably in a range of 0.1% by
weight to 50% by weight, more preferably in a range of 0.01% to 30%
by weight, and most preferably 0.1% to 10% by weight with respect
to an entire solid content. When the ratio is less than 0.01% by
weight, it is difficult to obtain an effect of addition of an
additive. On the other hand, when the ratio is more than 50% by
weight, it is difficult to reflect a characteristic of the
polyamide-imide in an end product. In other words, when a mixture
ratio of the optional component is 0.1% by weight with respect to a
whole solid content, an effect of addition of an additive can be
obtained. Therefore, the mixture ratio of 0.1% by weight is
preferable. Further, when the mixture ratio is 50% by weight or
less, the characteristic of the polyamide-imide tends to be
reflected in an end product. Therefore, the mixture ratio of 50% by
weight or less is preferable. Note that the solid content of the
polyamide-imide indicates all components except solvent. Therefore,
the solid content encompasses a liquid monomer component.
[0059] The polyamide-imide solution of the present invention is
formed into a film. Then, on a surface of the film, any of various
types of inorganic thin films such as a metal oxide film and a
transparent electrode film may be formed. A method for forming such
a film is not specifically limited but may be, for example, a CVD
method; or a PVD method such as a sputtering method, a vapor
deposition method, or an ion plating method.
[0060] The polyamide-imide solution of the present invention has a
high dimensional stability and a high solubility in an organic
solvent, in addition to characteristics, such as heat resistance,
insulating property, and the like, that are inherent in
polyamide-imide. Further, the polyamide-imide solution of the
present invention is excellent in coating applicability. Therefore,
the polyamide-imide solution of the present invention can be
suitably employed in fields or products in which the
above-described characteristics are effective. Examples of such
fields or products are: optical materials such as a printed matter,
a color filter, a flexible display substrate, a TFT substrate, an
optical film, and the like; an image display device such as a
liquid crystal display device, an organic EL, and the electronic
paper; an electronic device material; and solar cells. Further, the
polyamide-imide solution of the present invention can also be
applied as a replacement material for a portion for which glass is
currently used.
[0061] In other words, the invention of the subject application has
the following arrangements.
[0062] 1. A polyamide-imide solution including: an organic solvent;
and a polyamide-imide including a structure represented by the
following general formula (1), the organic solvent being a mixture
solvent of an amide solvent and a non-amide solvent, the non-amide
solvent being at least one solvent selected from the group
consisting of ether solvents, ketone solvents, ester solvents,
glycol ether solvents, and glycol ester solvents.
##STR00007##
[0063] More preferably, a polyamide-imide solution including: an
organic solvent; and a polyamide-imide represented by the above
general formula (1), the organic solvent being a mixture solvent of
an amide solvent and a non-amide solvent, the non-amide solvent
being at least one solvent selected from the group consisting of
ether solvents, ketone solvents, ester solvents, glycol ether
solvents, and glycol ester solvents.
[0064] 2. The polyamide-imide solution as set forth in 1, wherein a
weight ratio of the amide solvent and the non-amide solvent (amide
solvent/non-amide solvent) is in a range of 80/20 to 5/95.
More preferably, the polyamide-imide solution as set forth in claim
1, wherein a weight ratio of the amide solvent and the non-amide
solvent (amide solvent/non-amide solvent) is in a range of 80/20 to
10/90.
[0065] 3. The polyamide-imide solution as set forth in 1 or 2,
wherein: the polyamide-imide including the structure represented by
the general formula (1) is a polyamide-imide represented by the
general formula (6).
##STR00008##
[0066] 4. The polyamide-imide solution as set forth in any one of 1
to 3, wherein: the amide solvent is N,N-dimethylacetamide or
N,N-dimethylformamide; and the non-amide solvent is at least one
solvent selected from the group consisting of methyl ethyl ketone,
methyl isobutyl ketone, cyclohexanone, cyclopentanone,
propyleneglycol monomethylether acetate, methyl triglyme, methyl
tetraglyme, methyl monoglyme, methyl diglyme, ethyl monoglyme,
ethyl diglyme, butyl diglyme, and .gamma.-butyrolactone.
More preferably, the polyamide-imide solution as set forth in any
one of 1 to 3, wherein: the amide solvent is N,N-dimethylacetamide
or N,N-dimethylformamide; and the non-amide solvent is at least one
solvent selected from the group consisting of methyl ethyl ketone,
methyl isobutyl ketone, cyclohexanone, cyclopentanone,
propyleneglycol monomethylether acetate, and methyl triglyme.
[0067] 5. A polyamide-imide film including a polyamide-imide
including a structure represented by the general formula (1):
##STR00009##
the polyamide-imide film having a birefringence .DELTA.N of 0.040
or higher, the birefringence being expressed by .DELTA.N=Nxy-Nz,
where an in-plane refractive index is Nxy and a refractive index in
a thickness direction is Nz.
[0068] 6. A polyamide-imide film obtained by forming a film from a
polyamide-imide solution as set forth in any one of the above 1 to
4.
[0069] 7. The polyamide-imide film as set forth in 5, obtained by
forming a film from a polyamide-imide solution, the polyamide-imide
solution including: an organic solvent; and a polyamide-imide
including a structure represented by the general formula (1), the
organic solvent being a mixture solvent of an amide solvent and a
non-amide solvent, the non-amide solvent being at least one solvent
selected from the group consisting of ether solvents, ketone
solvents, ester solvents, glycol ether solvents, and glycol ester
solvents.
[0070] 8. The polyamide-imide film as set forth in 6 or 7, obtained
by applying the polyamide-imide solution onto a support.
[0071] 9. The polyamide-imide film as set forth in any one of 5 to
8, having a linear thermal expansion coefficient of 22 ppm/K or
less at a temperature in a range of 100.degree. C. to 300.degree.
C. More preferably, the polyamide-imide film as set forth in any
one of 5 to 8, having a linear thermal expansion coefficient of 20
ppm/K or less at a temperature in a range of 100.degree. C. to
300.degree. C.
[0072] 10. The polyamide-imide film as set forth in any one of 5 to
9 wherein: the birefringence .DELTA.N is 0.070 or more and 0.30 or
less, the birefringence .DELTA.N being expressed by
.DELTA.N=Nxy-Nz, where Nxy is an in-plane refractive index and Nz
is an refractive index.
[0073] 11. A laminate including: a polyamide-imide film as set
forth in any one of 5 to 10 above; and a glass substrate.
[0074] 12. A flexible display substrate including a polyamide-imide
film as set forth in any one of 5 to 10 above.
[0075] 13. A TFT substrate including a polyamide-imide film as set
forth in any one of 5 to 10 above.
[0076] 14. A color filter including a polyamide-imide film as set
forth in any one of 5 to 10 above.
[0077] 15. An electronic paper including a polyamide-imide film as
set forth in any one of 5 to 10 above.
[0078] 16. An organic EL display including a polyamide-imide film
as set forth in any one of 5 to 10 above.
EXAMPLES
Evaluation Method
[0079] The following evaluation method is used for obtaining
material characteristic values described in the present
specification.
[0080] (1) Molecular Weight of Polyamide-Imide
[0081] Under conditions shown in Table 1, weight-average molecular
weights (Mw) were obtained. Table 3 shows an evaluation result.
TABLE-US-00001 TABLE 1 Conditions of Item Apparatus for Molecular
Weight Measurement Apparatus CO-8020, SD-8022, DP-8020, AS-8020,
RI- 8020 (all manufactured by Tosoh Corporation) Column Shodex: GPC
KD-806M .times. 2 Column Size each 8 mm.PHI. .times. 30 cm, total
60 cm guard column (GPC KD-G) 4.6 mm.PHI. .times. 1 cm Column
40.degree. C. Temperature Eluent 30 mM-LiBr + 30 mM-phosphoric acid
DMF Flow Rate 0.6 mL/min Inlet approximately 1.3 to 1.7 MPa
Pressure Inlet Volume 30 .mu.L (solid content concentration 0.4 wt
%) Reference polyethylene oxide Sample (used for creation of
calibration curve) Detector RI Order of 1st Order Calibration
Curve
[0082] (2) Solubility Test of Polyamide-imide into Organic Solvent
and Odor Evaluation of Organic Solvent
[0083] With respect to 0.5 g of polyamide-imides respectively
obtained in Synthesis Examples 1, 2, and 3, 9.5 g of one of organic
solvents (solid content concentration 5%) shown in Table 2 was
mixed in a sample tube, and a resultant mixture was stirred at a
room temperature, more specifically, at 23.degree. C. by a magnetic
stirrer. Then, an organic solvent in which the polyamide-imide was
completely dissolved was evaluated as "Good"; an organic solvent in
which the polyamide-imide partially remained undissolved was
evaluated as "Fair"; and an organic solvent in which the
polyamide-imide was insoluble was evaluated as "Poor". Table 2
shows solvents used in the evaluation, respective boiling points of
the solvents, and a result of the evaluation. Further, odor of the
organic solvents was evaluated. An organic solvent that had
substantially no odor was evaluated as "Good"; an organic solvent
that had light odor was evaluated as "Fair"; and an organic solvent
that had distinct odor was evaluated as "Poor". Table 2 shows a
result of this evaluation. Further, organic solvents (including
mixture solvents) used in Examples and Comparative Examples of the
present invention were similarly evaluated. Table 3 shows a result
of this evaluation.
TABLE-US-00002 TABLE 2 Boiling Solubility Point Synthesis Synthesis
Synthesis Solvent (.degree. C.) Example 1 Example 2 Example 3 Odor
Tetrahydrofuran 65 Good Good Good Poor 1,3-dioxolan 75 Good Good
Good Poor 1,4-dioxane 101 Good Good Good Fair Cyclopentanone 130
Good Good Good Poor Cyclohexanone 155 Fair Fair Fair Poor Ethyl
acetate 77 Fair Fair Fair Poor .gamma.-butyrolactone 204 Fair Poor
Poor Good NMP 202 Fair Fair Fair Fair DMF 151 Good Good Good Fair
DMAC 166 Good Good Good Fair Methyltriglyme 216 Good Fair Good
Good
[0084] (3) Linear Thermal Expansion Coefficient of Film
(Polyamide-Imide Film)
[0085] The linear thermal expansion coefficient was measured as
follows, by using TMA120C manufactured by Seiko Electronics
Industrial Co., Ltd. (sample size: 3 mm (width) by 10 mm (length);
TMA120C measures a thickness of the sample and calculates a film
cross sectional area). First, a temperature was increased (first
temperature increase) at 10.degree. C./min from 10.degree. C. up to
340.degree. C. under the load of 3 g. Then, the temperature was
decreased to 10.degree. C. Further, the temperature was increased
(second temperature increase) at 10.degree. C./min up to
340.degree. C. again. From an amount of change in deformation of a
sample for each of (a) a unit temperature from 100.degree. C. to
200.degree. C. and (b) a unit temperature from 100.degree. C. to
300.degree. C. in the second temperature increase, the linear
thermal expansion coefficient was obtained.
[0086] (4) Glass Transition Temperature of Film
[0087] By using DMS-200 manufactured by Seiko Electronics
Industrial Co., Ltd., a dynamic viscoelasticity was measured under
a condition in which a length for measurement (measurement jig
interval) was set at 20 mm and a frequency for measurement was set
at 1 Hz. Then, an inflection point (a peak top of tan 6) of a
storage elastic modulus was taken as a glass transition
temperature.
[0088] (5) Birefringence of Film (Polyamide-Imide Film)
[0089] As an index indicating a degree (in-plane orientation
degree) at which high molecular chains are oriented in parallel to
a film surface, a birefringence was measured. Here, the
birefringence (.DELTA.N) is a value expressed by .DELTA.N=Nxy-Nz,
where: Nxy is an in-plane refractive index of the polyamide-imide
film; and Nz is a refractive index in a thickness direction. The
refractive index was measured by using Abbe refractometer (DR-M2)
(manufactured by ATAGO Co., Ltd.) where an eyepiece with a
polarizer was set. In this measurement, on a film that was cut so
as to have a size of 40 mm.times.8 mm was measured. A polarization
direction was changed by altering a direction of the polarizer, so
that both the in-plane refractive index and the refractive index in
the thickness direction were measured. In the measurement, a
wavelength for the measurement was a wavelength of a sodium lamp
(589 nm) that was used as a light source; an intermediate liquid
was sulfur saturated methylene iodide; and a test piece had a
refractive index of 1.92.
[0090] (6) Evaluation of Whitening in Application Process
[0091] The polyamide-imide solution was applied onto a glass
substrate that was a support so as to prepare a wet film. This wet
film was observed in an environment at a temperature of 23.degree.
C. and a relative humidity of 55% RH, and a time (time before
whitening) elapsed before whitening of the wet film started was
measured. In a case where the time elapsed before whitening started
was equal to or longer than 5 minutes, it was judged that whitening
in an application process was suppressed.
[0092] (7) Tack-Free Evaluation
[0093] The polyamide-imide solution was applied onto a glass
substrate that was a support so as to prepare a wet film. This wet
film was observed in an environment at a temperature of 23.degree.
C. and a relative humidity of 55% RH, and a time elapsed before a
surface dried and a tack-free state was established was measured.
In a case where thus measured time was equal to or longer than 10
minutes, it was judged that long-lasting application processability
during application process was preferable.
Synthesis Example 1
Synthesis of Polyamide-Imide
[0094] In a 2 L glass separable flask equipped with (i) a stirrer
including a stainless-steel stirring rod with an impeller provided
to a polytetrafluoroethylene sealing plug and (ii) a nitrogen inlet
tube, 12.1 g of 2,2'-bis(trifluoromethyl)benzidine (hereinafter,
also referred to as TFMB) was introduced. To this TFMB, 46.6 g of
dehydrated N,N-dimethylacetamide (DMAC) was added as a solvent for
polymerization and stirring was carried out. Further, 3.0 g of
pyridine was added and then, thus obtained solution was stirred
until a uniform solution was obtained. Then, the solution was
cooled in an ice bath at 5.degree. C. While the solution was being
stirred, 7.9 g of trimellitic anhydride chloride powder was slowly
added and then 3-hour stirring was carried out in an ice bath at
5.degree. C. Note that a concentration of solutes in thus obtained
solution, that is, a concentration of a diamine compound and
trimellitic anhydride chloride added in the solution was 30% by
weight with respect to a whole reaction solution.
[0095] After the 3-hour stirring, the solution was diluted by
addition of 33.4 g of DMAC into the solution. Then, after 20-hour
stirring was carried out in a water bath at 25.degree. C., 33.3 g
of DMAC was further added. Then, stirring was carried out until
this DMAC was uniformly dissolved. Subsequently, 6.0 g of pyridine
was added as an imidization catalyst and dispersed completely. Into
thus obtained solution, 9.2 g of acetic anhydride was added and
stirring was carried out. Subsequently, 4-hour stirring was carried
out at 100.degree. C., and then the solution was cooled down to a
room temperature (23.degree. C.). To thus cooled solution, 33.3 g
of DMAC was further added and stirring was carried out. While the
solution was kept being stirred, 350 g of 2-propyl alcohol
(hereinafter, IPA) was added at a rate of 2 to 3 drops/sec by use
of a dropping funnel. As a result, a target product was
precipitated. Then, suction filtration was carried out with use of
Kiriyama rohto (funnel) and the target product was washed 5 times
repeatedly with 200 g of IPA. Thereafter, the target product was
dried for 12 hours in a vacuum oven set at 120.degree. C. As a
result, the target product was obtained at a yield of 17.0 g.
Example 1
Preparation of Film
[0096] The polyamide-imide obtained in Synthesis Example 1 was
dissolved in a mixture solvent of DMAC and cyclopentanone
(hereinafter, CPN) at a weight ratio of DMAC/CPN=70/30, and thereby
a polyamide-imide solution containing 7% by weight of
polyamide-imide was prepared. After applying this polyamide-imide
solution on a glass plate that was a support, dehydration was
carried out first at 60.degree. C. for 10 minutes, then at
150.degree. C. for 60 minutes, and further at 300.degree. C. for 60
minutes. Then, a film was obtained by peeling the film off from the
glass plate. Table 3 shows an evaluation result of thus obtained
film.
Example 2
[0097] The polyamide-imide obtained in Synthesis Example 1 was
dissolved in a mixture solvent of DMAC and CPN at a weight ratio of
DMAC/CPN=50/50, and thereby a polyamide-imide solution containing
7% by weight of polyamide-imide was prepared. After applying this
polyamide-imide solution on a glass plate that was a support,
dehydration was carried out first at 60.degree. C. for 10 minutes,
then at 150.degree. C. for 60 minutes, and further at 300.degree.
C. for 60 minutes. Then, a film was obtained by peeling the film
off from the glass plate. Table 3 shows an evaluation result of
thus obtained film.
Example 3
[0098] The polyamide-imide obtained in Synthesis Example 1 was
dissolved in a mixture solvent of DMAC and cyclohexanone
(hereinafter, CHN) at a weight ratio of DMAC/CHN=70/30, and thereby
a polyamide-imide solution containing 10% by weight of
polyamide-imide was prepared. After applying this polyamide-imide
solution on a glass plate that was a support, dehydration was
carried out first at 60.degree. C. for 10 minutes, then at
150.degree. C. for 60 minutes, and further at 300.degree. C. for 60
minutes. Then, a film was obtained by peeling the film off from the
glass plate. Table 3 shows an evaluation result of thus obtained
film.
Example 4
[0099] The polyamide-imide obtained in Synthesis Example 1 was
dissolved in a mixture solvent of DMAC and CHN at a weight ratio of
DMAC/CHN=50/50, and thereby a polyamide-imide solution containing
10% by weight of polyamide-imide was prepared. After applying this
polyamide-imide solution on a glass plate that was a support,
dehydration was carried out first at 60.degree. C. for 10 minutes,
then at 150.degree. C. for 60 minutes, and further at 300.degree.
C. for 60 minutes. Then, a film was obtained by peeling the film
off from the glass plate. Table 3 shows an evaluation result of
thus obtained film.
Example 5
[0100] The polyamide-imide obtained in Synthesis Example 1 was
dissolved in a mixture solvent of DMAC and propyleneglycol
monomethylether acetate (hereinafter, PGMEA) at a weight ratio of
DMAC/PGMEA=70/30, and thereby a polyamide-imide solution containing
10% by weight of polyamide-imide was prepared. After applying this
polyamide-imide solution on a glass plate that was a support,
dehydration was carried out first at 60.degree. C. for 10 minutes,
then at 150.degree. C. for 60 minutes, and further at 300.degree.
C. for 60 minutes. Then, a film was obtained by peeling the film
off from the glass plate. Table 3 shows an evaluation result of
thus obtained film.
Example 6
[0101] The polyamide-imide obtained in Synthesis Example 1 was
dissolved in a mixture solvent of DMF and CPN at a weight ratio of
DMF/CPN=50/50, and thereby a polyamide-imide solution containing
10% by weight of polyamide-imide was prepared. After applying this
polyamide-imide solution on a glass plate that was a support,
dehydration was carried out first at 60.degree. C. for 10 minutes,
then at 150.degree. C. for 60 minutes, and further at 300.degree.
C. for 60 minutes. Then, a film was obtained by peeling the film
off from the glass plate. Table 3 shows an evaluation result of
thus obtained film.
Example 7
[0102] The polyamide-imide obtained in Synthesis Example 1 was
dissolved in a mixture solvent of DMF and CHN at a weight ratio of
DMF/CHN=50/50, and thereby a polyamide-imide solution containing
10% by weight of polyamide-imide was prepared. After applying this
polyamide-imide solution on a glass plate that was a support,
dehydration was carried out first at 60.degree. C. for 10 minutes,
then at 150.degree. C. for 60 minutes, and further at 300.degree.
C. for 60 minutes. Then, a film was obtained by peeling the film
off from the glass plate. Table 3 shows an evaluation result of
thus obtained film.
Synthesis Example 2
Synthesis of Amide-Group-Containing Tetracarboxylic Dianhydride
(Formula (7) Below)
##STR00010##
[0104] In a 500 mL glass separable flask equipped with (i) a
stirrer including a stainless-steel stirring rod with a four-blade
impeller provided to a polytetrafluoroethylene sealing plug and
(ii) a nitrogen inlet tube, 67.4 g of trimellitic anhydride
chloride was introduced. Then, a mixture solvent including 190 g of
ethyl acetate and 190 g of n-hexane was added and the trimellitic
anhydride chloride was dissolved, so that a solution A was
prepared. Further, in another container, 25.6 g of
2,2'-bis(trifluoromethyl)benzidine (TFMB) was provided and a
mixture solvent including 72 g of ethyl acetate and 72 g of
n-hexane was added, so that the TFMB was dissolved in the mixture
solvent. Further, 9.2 g of propylene oxide was added as a
deoxidizer and thereby, a solution B was prepared.
[0105] To the solution A whose temperature was lowered to
approximately -20.degree. C. in an ethanol ice bath, the solution B
was dropped under stirring. Then, 3-hour stirring was carried out.
Subsequently, thus obtained solution was stirred for 12 hours at a
room temperature (23.degree. C.). A resultant precipitate was
separated by filtration and washed well with an ethyl
acetate/n-hexane mixture solvent (volume ratio: 1:1). Thereafter,
separation by filtration was carried out again and vacuum
dehydration was carried out first at 60.degree. C. for 12 hours,
and then at 120.degree. C. for 12 hours. Thereby, a resultant white
product was obtained at a yield of 70%. By FT-IR and .sup.1H-NMR,
it was confirmed that an amide-group-containing tetracarboxylic
dianhydride represented by the formula (7), which was a target
product, was obtained. Specifically, it was possible to observe (i)
by FT-IR, peaks at 3380 cm.sup.-1 (amide group NH stretching
vibration), 3105 cm.sup.-1 (aromatic C--H stretching vibration),
1857 cm.sup.-1 and 1781 cm.sup.-1 (acid anhydride group C.dbd.O
stretching vibration), and 1677 cm.sup.-1 (amide group C.dbd.O
stretching vibration) and (ii) by .sup.1H-NMR, peaks at 611.06 ppm
(s, NH, 2H), 68.65 ppm (s, on phthalic anhydride, 3-position
C.sub.aromH, 2H), 68.37 ppm (5,6-position C.sub.aromH on phthalic
anhydride, 4H), 67.46 ppm (d, on central biphenyl, 6,6'-position
C.sub.aromH, 2H), 68.13 ppm (d, on central biphenyl, 5,5'-position
C.sub.aromH, 2H), and 68.27 ppm (s, on central biphenyl,
3,3'-position C.sub.aromH, 2H); this proves that the
amide-group-containing tetracarboxylic dianhydride as represented
by the above formula (7) was obtained. As a result of measurement
of a melting point of this compound by DSC, the melting point of
this compound was found to be 274.degree. C.
Synthesis of Polyamide-Imide
[0106] In a 500 mL glass separable flask equipped with (i) a
stirrer including a stainless-steel stirring rod with a four-blade
impeller provided to a polytetrafluoroethylene sealing plug and
(ii) a nitrogen inlet tube, 9.7 g of TFMB was introduced. Then, 153
g of dehydrated N,N-dimethylformamide (DMF) was added as a solvent
for polymerization. After thus obtained solution was stirred, 20.2
g of the amide-group-containing tetracarboxylic dianhydride as
represented by the above formula (7) was added to the solution.
After 10-minute stirring, 17 g of acetic acid was added. Then,
stirring at a room temperature (23.degree. C.) was carried out and
thereby, polyamide-amide acid was obtained. Note that in thus
obtained solution, a concentration of a diamine compound and
tetracarboxylic dianhydride added in the solution was 15% by weight
with respect to a whole reaction solution.
[0107] After 24-hour stirring, 4.8 g of pyridine was added as an
imidization catalyst and completely dispersed. Into thus obtained
solution, 7.4 g of acetic anhydride was added and stirring was
carried out. Then, after 4-hour stirring was carried out at
100.degree. C., a resultant solution was cooled down to the room
temperature (23.degree. C.). Into this solution, 88 g of DMF was
added and stirring was carried out. Thus obtained solution was
transferred to a 2 L separable flask. Into the solution, 600 g of
IPA was further added at a rate of 2 to 3 drops/sec. Thereby, a
target product was precipitated. Then, suction filtration was
carried out with use of Kiriyama rohto (funnel) and the target
product was washed 2 times repeatedly with 300 g of IPA.
Thereafter, the target product was dried overnight in a vacuum oven
set at 100.degree. C. As a result, the target product was obtained
at a yield of 28.5 g.
Example 8
Preparation of Film
[0108] The polyamide-imide obtained in Synthesis Example 2 was
dissolved in a mixture solvent of DMAC and CPN at a weight ratio of
DMAC/CPN=70/30, and thereby a polyamide-imide solution containing
7% by weight of polyamide-imide was prepared. After applying this
polyamide-imide solution on a glass plate that was a support,
dehydration was carried out first at 60.degree. C. for 10 minutes,
then at 150.degree. C. for 60 minutes, and further at 300.degree.
C. for 60 minutes. Then, a film was obtained by peeling the film
off from the glass plate. Table 3 shows an evaluation result of
thus obtained film.
Example 9
[0109] The polyamide-imide obtained in Synthesis Example 2 was
dissolved in a mixture solvent of DMAC and CPN at a weight ratio of
DMAC/CPN=50/50, and thereby a polyamide-imide solution containing
7% by weight of polyamide-imide was prepared. After applying this
polyamide-imide solution on a glass plate that was a support,
dehydration was carried out first at 60.degree. C. for 10 minutes,
then at 150.degree. C. for 60 minutes, and further at 300.degree.
C. for 60 minutes. Then, a film was obtained by peeling the film
off from the glass plate. Table 3 shows an evaluation result of
thus obtained film.
Example 10
[0110] The polyamide-imide obtained in Synthesis Example 2 was
dissolved in a mixture solvent of DMAC and CHN at a weight ratio of
DMAC/CHN=70/30, and thereby a polyamide-imide solution containing
7% by weight of polyamide-imide was prepared. After applying this
polyamide-imide solution on a glass plate that was a support,
dehydration was carried out first at 60.degree. C. for 10 minutes,
then at 150.degree. C. for 60 minutes, and further at 300.degree.
C. for 60 minutes. Then, a film was obtained by peeling the film
off from the glass plate. Table 3 shows an evaluation result of
thus obtained film.
Example 11
[0111] The polyamide-imide obtained in Synthesis Example 2 was
dissolved in a mixture solvent of DMAC and CHN at a weight ratio of
DMAC/CHN=50/50, and thereby a polyamide-imide solution containing
7% by weight of polyamide-imide was prepared. After applying this
polyamide-imide solution on a glass plate that was a support,
dehydration was carried out first at 60.degree. C. for 10 minutes,
then at 150.degree. C. for 60 minutes, and further at 300.degree.
C. for 60 minutes. Then, a film was obtained by peeling the film
off from the glass plate. Table 3 shows an evaluation result of
thus obtained film.
Example 12
[0112] The polyamide-imide obtained in Synthesis Example 2 was
dissolved in a mixture solvent of DMAC and PGMEA at a weight ratio
of DMAC/PGMEA=70/30, and thereby a polyamide-imide solution
containing 7% by weight of polyamide-imide was prepared. After
applying this polyamide-imide solution on a glass plate that was a
support, dehydration was carried out first at 60.degree. C. for 10
minutes, then at 150.degree. C. for 60 minutes, and further at
300.degree. C. for 60 minutes. Then, a film was obtained by peeling
the film off from the glass plate. Table 3 shows an evaluation
result of thus obtained film.
Example 13
[0113] The polyamide-imide obtained in Synthesis Example 2 was
dissolved in a mixture solvent of DMF and CPN at a weight ratio of
DMF/CPM=50/50, and thereby a polyamide-imide solution containing 7%
by weight of polyamide-imide was prepared. After applying this
polyamide-imide solution on a glass plate that was a support,
dehydration was carried out first at 60.degree. C. for 10 minutes,
then at 150.degree. C. for 60 minutes, and further at 300.degree.
C. for 60 minutes. Then, a film was obtained by peeling the film
off from the glass plate. Table 3 shows an evaluation result of
thus obtained film.
Example 14
[0114] The polyamide-imide obtained in Synthesis Example 2 was
dissolved in a mixture solvent of DMF and CHN at a weight ratio of
DMF/CHN=50/50, and thereby a polyamide-imide solution containing 7%
by weight of polyamide-imide was prepared. After applying this
polyamide-imide solution on a glass plate that was a support,
dehydration was carried out first at 60.degree. C. for 10 minutes,
then at 150.degree. C. for 60 minutes, and further at 300.degree.
C. for 60 minutes. Then, a film was obtained by peeling the film
off from the glass plate. Table 3 shows an evaluation result of
thus obtained film.
Example 15
[0115] The polyamide-imide obtained in Synthesis Example 1 was
dissolved in a mixture solvent of DMAC and methyltriglyme
(hereinafter, MTG) at a weight ratio of DMAC/MTG=20/80, and thereby
a polyamide-imide solution containing 7% by weight of
polyamide-imide was prepared. After applying this polyamide-imide
solution on a glass plate that was a support, dehydration was
carried out f first at 60.degree. C. for 10 minutes, then at
150.degree. C. for 60 minutes, and further at 300.degree. C. for 60
minutes. Then, a film was obtained by peeling the film off from the
glass plate. Table 3 shows an evaluation result of thus obtained
film.
Synthesis Example 3
Synthesis of Polyamide-Imide
[0116] In a 500 mL glass separable flask equipped with (i) a
stirrer including a stainless-steel stirring rod with a four-blade
impeller provided to a polytetrafluoroethylene sealing plug and
(ii) a nitrogen inlet tube, 9.8 g of TFMB was introduced. Then, 153
g of dehydrated N,N-dimethylformamide (DMF) was added as a solvent
for polymerization. After thus obtained solution was stirred, 20.1
g of the amide-group-containing tetracarboxylic dianhydride as
represented by the above formula (7) was added to the solution.
After 10-minute stirring, 17 g of acetic acid was added. Then,
stirring at a room temperature (23.degree. C.) was carried out and
thereby, polyamide-amide acid was obtained. Note that in thus
obtained solution, a concentration of a diamine compound and
tetracarboxylic dianhydride added in the solution was 15% by weight
with respect to a whole reaction solution.
[0117] After 24-hour stirring, 4.8 g of pyridine was added as an
imidization catalyst and completely dispersed. Into thus obtained
solution, 7.4 g of acetic anhydride was added and stirring was
carried out. Then, after 4-hour stirring was carried out at
100.degree. C., a resultant solution was cooled down to the room
temperature (23.degree. C.). Into this solution, 88 g of DMF was
added and stirring was carried out. Thus obtained solution was
transferred to a 2 L separable flask. Into the solution, 600 g of
IPA was further added at a rate of 2 to 3 drops/sec. Thereby, a
target product was precipitated. Then, suction filtration was
carried out with use of Kiriyama rohto (funnel) and the target
product was washed 2 times repeatedly with 300 g of IPA.
Thereafter, the target product was dried overnight in a vacuum oven
set at 100.degree. C. As a result, the target product was obtained
at a yield of 28.5 g.
Example 16
[0118] The polyamide-imide obtained in Synthesis Example 3 was
dissolved in a mixture solvent of DMAC and MTG at a weight ratio of
DMAC/MTG=30/70, and thereby a polyamide-imide solution containing
7% by weight of polyamide-imide was prepared. After applying this
polyamide-imide solution on a glass plate that was a support,
dehydration was carried out first at 60.degree. C. for 10 minutes,
then at 150.degree. C. for 60 minutes, and further at 300.degree.
C. for 60 minutes. Then, a film was obtained by peeling the film
off from the glass plate. Table 3 shows an evaluation result of
thus obtained film.
Example 17
[0119] The polyamide-imide obtained in Synthesis Example 3 was
dissolved in a mixture solvent of DMAC and .gamma.-butyrolactone
(GBL) at a weight ratio of DMAC/GBL=50/50, and thereby a
polyamide-imide solution containing 7% by weight of polyamide-imide
was prepared. After applying this polyamide-imide solution on a
glass plate that was a support, dehydration was carried out first
at 60.degree. C. for 10 minutes, then at 150.degree. C. for 60
minutes, and further at 300.degree. C. for 60 minutes. Then, a film
was obtained by peeling the film off from the glass plate. Table 3
shows an evaluation result of thus obtained film.
Comparative Example 1
[0120] The polyamide-imide obtained in Synthesis Example 1 was
dissolved in DMAC and thereby a polyamide-imide solution containing
10% by weight of polyamide-imide was prepared. After applying this
polyamide-imide solution on a glass plate that was a support,
dehydration was carried out first at 60.degree. C. for 10 minutes,
then at 150.degree. C. for 60 minutes, and further at 300.degree.
C. for 60 minutes. Then, a film was obtained by peeling the film
off from the glass plate. Table 3 shows an evaluation result of
thus obtained film.
Comparative Example 2
[0121] The polyamide-imide obtained in Synthesis Example 1 was
dissolved in DMF, and thereby a polyamide-imide solution containing
10% by weight of polyamide-imide was prepared. After applying this
polyamide-imide solution on a glass plate that was a support,
dehydration was carried out first at 60.degree. C. for 10 minutes,
then at 150.degree. C. for 60 minutes, and further at 300.degree.
C. for 60 minutes. Then, a film was obtained by peeling the film
off from the glass plate. Table 3 shows an evaluation result of
thus obtained film.
Comparative Example 3
[0122] The polyamide-imide obtained in Synthesis Example 1 was
dissolved in tetrahydrofuran (hereinafter, THF), and thereby a
polyamide-imide solution containing 10% by weight of
polyamide-imide was prepared. After applying this polyamide-imide
solution on a glass plate that was a support, dehydration was
carried out first at 60.degree. C. for 10 minutes, then at
150.degree. C. for 60 minutes, and further at 300.degree. C. for 60
minutes. Then, a film was obtained by peeling the film off from the
glass plate. Table 3 shows an evaluation result of thus obtained
film.
Comparative Example 4
[0123] The polyamide-imide obtained in Synthesis Example 1 was
dissolved in 1,3-dioxolan, and thereby a polyamide-imide solution
containing 10% by weight of polyamide-imide was prepared. After
applying this polyamide-imide solution on a glass plate that was a
support, dehydration was carried out first at 60.degree. C. for 10
minutes, then at 150.degree. C. for 60 minutes, and further at
300.degree. C. for 60 minutes. Then, a film was obtained by peeling
the film off from the glass plate. Table 3 shows an evaluation
result of thus obtained film.
Comparative Example 5
[0124] The polyamide-imide obtained in Synthesis Example 1 was
dissolved in 1,4-dioxane, and thereby a polyamide-imide solution
containing 10% by weight of polyamide-imide was prepared. After
applying this polyamide-imide solution on a glass plate that was a
support, dehydration was carried out first at 60.degree. C. for 10
minutes, then at 150.degree. C. for 60 minutes, and further at
300.degree. C. for 60 minutes. Then, a film was obtained by peeling
the film off from the glass plate. Table 3 shows an evaluation
result of thus obtained film.
Comparative Example 6
[0125] The polyamide-imide obtained in Synthesis Example 2 was
dissolved in DMAC, and thereby a polyamide-imide solution
containing 7% by weight of polyamide-imide was prepared. After
applying this polyamide-imide solution on a glass plate that was a
support, dehydration was carried out first at 60.degree. C. for 10
minutes, then at 150.degree. C. for 60 minutes, and further at
300.degree. C. for 60 minutes. Then, a film was obtained by peeling
the film off from the glass plate. Table 3 shows an evaluation
result of thus obtained film.
Comparative Example 7
[0126] The polyamide-imide obtained in Synthesis Example 2 was
dissolved in DMF and thereby a polyamide-imide solution containing
7% by weight of polyamide-imide was prepared. After applying this
polyamide-imide solution on a glass plate that was a support,
dehydration was carried out first at 60.degree. C. for 10 minutes,
then at 150.degree. C. for 60 minutes, and further at 300.degree.
C. for 60 minutes. Then, a film was obtained by peeling the film
off from the glass plate. Table 3 shows an evaluation result of
thus obtained film.
Comparative Example 8
[0127] The polyamide-imide obtained in Synthesis Example 2 was
dissolved in THF and thereby a polyamide-imide solution containing
7% by weight of polyamide-imide was prepared. After applying this
polyamide-imide solution on a glass plate that was a support,
dehydration was carried out first at 60.degree. C. for 10 minutes,
then at 150.degree. C. for 60 minutes, and further at 300.degree.
C. for 60 minutes. Then, a film was obtained by peeling the film
off from the glass plate. Table 3 shows an evaluation result of
thus obtained film.
Comparative Example 9
[0128] The polyamide-imide obtained in Synthesis Example 2 was
dissolved in 1,3-dioxolan and thereby a polyamide-imide solution
containing 7% by weight of polyamide-imide was prepared. After
applying this polyamide-imide solution on a glass plate that was a
support, dehydration was carried out first at 60.degree. C. for 10
minutes, then at 150.degree. C. for 60 minutes, and further at
300.degree. C. for 60 minutes. Then, a film was obtained by peeling
the film off from the glass plate. Table 3 shows an evaluation
result of thus obtained film.
Comparative Example 10
[0129] The polyamide-imide obtained in Synthesis Example 2 was
dissolved in 1,4-dioxane and thereby a polyamide-imide solution
containing 7% by weight of polyamide-imide was prepared. After
applying this polyamide-imide solution on a glass plate that was a
support, dehydration was carried out first at 60.degree. C. for 10
minutes, then at 150.degree. C. for 60 minutes, and further at
300.degree. C. for 60 minutes. Then, a film was obtained by peeling
the film off from the glass plate. Table 3 shows an evaluation
result of thus obtained film.
Synthesis Example 4
[0130] In a 500 mL glass separable flask equipped with (i) a
stirrer including a stainless-steel stirring rod with a four-blade
impeller provided to a polytetrafluoroethylene sealing plug and
(ii) a nitrogen inlet tube, 9.7 g of TFMB was introduced. Then, 170
g of dehydrated N,N-dimethylformamide (DMF) was added as a solvent
for polymerization. After thus obtained solution was stirred, 20.2
g of the amide-group-containing tetracarboxylic dianhydride as
represented by the above formula (7) was added. Then, stirring at a
room temperature (23.degree. C.) was carried out and thereby,
polyamide-amide acid was obtained. Note that in thus obtained
solution, a concentration of a diamine compound and tetracarboxylic
dianhydride added in the solution was 15% by weight with respect to
a whole reaction solution. To this reaction solution, 100 g of DMF
was added so that a concentration of DMF added was adjusted to be
10% by weight. Thereby, polyamide-amide acid was obtained.
Comparative Example 11
Preparation of Film
[0131] The polyamide-amide acid solution obtained in Synthesis
Example 4 was applied on a glass plate that was a support. Further,
dehydration was carried out first at 60.degree. C. for 10 minutes,
then at 150.degree. C. for 60 minutes, and further at 300.degree.
C. for 60 minutes. Then, a film was obtained by peeling the film
off from the glass plate. Table 3 shows an evaluation result of
thus obtained film.
Comparative Example 12
[0132] The polyamide-imide film obtained in Comparative Example 11
was dissolved again in DMAC, and thereby a polyamide-imide solution
containing 7% by weight of polyamide-imide was prepared. After
applying this polyamide-imide solution on a glass plate that was a
support, dehydration was carried out first at 60.degree. C. for 10
minutes, then at 150.degree. C. for 60 minutes, and further at
300.degree. C. for 60 minutes. Then, a film was obtained by peeling
the film off from the glass plate. Table 3 shows an evaluation
result of thus obtained film.
Comparative Example 13
[0133] The polyamide-imide obtained in Synthesis Example 1 was
dissolved in MTG, and thereby a polyamide-imide solution containing
7% by weight of polyamide-imide was prepared. After applying this
polyamide-imide solution on a glass plate that was a support,
dehydration was carried out first at 60.degree. C. for 10 minutes,
then at 150.degree. C. for 60 minutes, and further at 300.degree.
C. for 60 minutes. Then, a film was obtained by peeling the film
off from the glass plate. Table 3 shows an evaluation result of
thus obtained film.
Comparative Example 14
[0134] The polyamide-imide obtained in Synthesis Example 2 was
dissolved in a mixture solvent of DMAC and DMF at a weight ratio of
DMAC/DMF=50/50, and thereby a polyamide-imide solution containing
7% by weight of polyamide-imide was prepared. After applying this
polyamide-imide solution on a glass plate that was a support,
dehydration was carried out first at 60.degree. C. for 10 minutes,
then at 150.degree. C. for 60 minutes, and further at 300.degree.
C. for 60 minutes. Then, a film was obtained by peeling the film
off from the glass plate. Table 3 shows an evaluation result of
thus obtained film.
Synthesis Example 5
[0135] In a 500 mL glass separable flask equipped with (i) a
stirrer including a stainless-steel stirring rod with a four-blade
impeller provided to a polytetrafluoroethylene sealing plug and
(ii) a nitrogen inlet tube, 9.7 g of TFMB was introduced. Then, 170
g of dehydrated DMAC was added as a solvent for polymerization.
After thus obtained solution was stirred, 20.4 g of the
amide-group-containing tetracarboxylic dianhydride as represented
by the above formula (7) was added. Then, stirring at a room
temperature (23.degree. C.) was carried out and thereby,
polyamide-amide acid was obtained. Note that in thus obtained
solution, a concentration of a diamine compound and tetracarboxylic
dianhydride added in the solution was 15% by weight with respect to
a whole reaction solution. To this reaction solution, 100 g of DMAC
was added so that a concentration of DMAC added was adjusted to be
10% by weight. Thereby, polyamide-amid acid was obtained.
Comparative Example 15
[0136] The polyamide-amide acid solution obtained in Synthesis
Example 5 was applied on a glass plate that was a support. Further,
dehydration was carried out first at 60.degree. C. for 10 minutes,
then at 150.degree. C. for 60 minutes, and further at 300.degree.
C. for 60 minutes. Then, a film was obtained by peeling the film
off from the glass plate. Table 3 shows an evaluation result of
thus obtained film.
TABLE-US-00003 TABLE 3 Molecular Synthesis Weight Film Thickness
Examples Solvent 1 Solvent 2 Solvent 1/Solvent 2 (Mw) (.mu.m)
Example 1 Synthesis DMAC CPN 70/30 100,000 30 Example 1 Example 2
Synthesis DMAC CPN 50/50 100,000 31 Example 1 Example 3 Synthesis
DMAC CHN 70/30 100,000 29 Example 1 20 Example 4 Synthesis DMAC CHN
50/50 100,000 30 Example 1 20 Example 5 Synthesis DMAC PGMEA 70/30
100,000 30 Example 1 Example 6 Synthesis DMF CPN 50/50 100,000 28
Example 1 Example 7 Synthesis DMF CHN 50/50 100,000 28 Example 1
Example 8 Synthesis DMAC CPN 70/30 150,000 27 Example 2 Example 9
Synthesis DMAC CPN 50/50 150,000 28 Example 2 Example 10 Synthesis
DMAC CHN 70/30 150,000 27 Example 2 20 Example 11 Synthesis DMAC
CHN 50/50 150,000 27 Example 2 20 Example 12 Synthesis DMAC PGMEA
70/30 150,000 28 Example 2 Example 13 Synthesis DMF CPN 50/50
150,000 29 Example 2 Example 14 Synthesis DMF CHN 50/50 150,000 29
Example 2 Example 15 Synthesis DMAC MTG 20/80 100,000 30 Example 1
20 Example 16 Synthesis DMAC MTG 30/70 130,000 30 Example 3 20
Example 17 Synthesis DMAC GBL 50/50 130,000 30 Example 3
Comparative Synthesis DMAC -- -- 100,000 30 Example 1 Example 1
Comparative Synthesis DMF -- -- 100,000 30 Example 2 Example 1
Comparative Synthesis THF -- -- 100,000 30 Example 3 Example 1
Comparative Synthesis 1,3- -- -- 100,000 30 Example 4 Example 1
dioxolane Comparative Synthesis 1,4- -- -- 100,000 30 Example 5
Example 1 dioxane Comparative Synthesis DMAC -- -- 150,000 30
Example 6 Example 2 Comparative Synthesis DMF -- -- 150,000 28
Example 7 Example 2 Comparative Synthesis THF -- -- 150,000 30
Example 8 Example 2 Comparative Synthesis 1,3- -- -- 150,000 30
Example 9 Example 2 dioxolane Comparative Synthesis 1,4- -- --
150,000 30 Example 10 Example 2 dioxane Comparative Synthesis DMF
-- -- 130,000 32 Example 11 Example 4 Comparative Synthesis DMAC --
-- 130,000 31 Example 12 Example 4 Comparative Synthesis MTG -- --
100,000 20 Example 13 Example 1 Comparative Synthesis DMAC DMF
50/50 150,000 30 Example 14 Example 2 DMF 50/50 150,000 20
Comparative Synthesis DMAC -- -- 160,000 30 Example 15 Example 5
Linear Thermal Expansion Coefficient Glass (CTE) Transition Time
100-200.degree. C. 100-300.degree. C. In-plane Temperature before
Tack- (ppm/ (ppm/ Birefringence Tg Whitening free K) k) .DELTA.N
(.degree. C.) min min Odor Example 1 15 22 0.080 350 15 50 Poor
Example 2 14 20 0.081 350 20 45 Poor Example 3 15 20 0.080 350 15
50 Poor 10 15 0.080 350 15 50 Poor Example 4 14 20 0.081 350 20 45
Poor 10 15 0.081 350 20 45 Poor Example 5 13 19 0.082 350 10 50
Poor Example 6 15 22 0.080 350 20 45 Poor Example 7 15 21 0.080 350
20 45 Poor Example 8 7 10 0.090 350 15 50 Poor Example 9 8 12 0.090
350 20 45 Poor Example 10 8 10 0.093 350 15 50 Poor 7 10 0.093 350
15 50 Poor Example 11 8 11 0.092 350 20 45 Poor 7 10 0.092 350 20
45 Poor Example 12 8 12 0.090 350 10 50 Poor Example 13 8 12 0.091
350 20 60 Poor Example 14 8 12 0.090 350 20 60 Poor Example 15 15
22 0.075 350 60 60 Good 14 20 0.075 350 60 60 Good Example 16 14 20
0.080 350 60 60 Good 13 18 0.080 350 60 60 Good Example 17 10 15
0.081 350 5 60 Good Comparative 15 22 0.078 350 2 60 Fair Example 1
Comparative 15 22 0.078 350 2 60 Fair Example 2 Comparative 9 13
0.090 350 15 5 Poor Example 3 Comparative 9 13 0.088 350 15 7 Poor
Example 4 Comparative 9 13 0.090 350 20 9 Fair Example 5
Comparative 9 12 0.088 350 3 60 Fair Example 6 Comparative 9 12
0.089 350 3 60 Fair Example 7 Comparative 7 10 0.095 350 15 5 Poor
Example 8 Comparative 7 11 0.094 350 15 7 Poor Example 9
Comparative 7 11 0.094 350 20 9 Fair Example 10 Comparative 38 55
0.024 350 5 60 Fair Example 11 Comparative 18 26 0.076 350 3 60
Fair Example 12 Comparative 17 23 0.080 350 60 60 Good Example 13
Comparative 9 12 0.090 350 2 60 Fair Example 14 7 10 0.090 350 2 60
Fair Comparative 35 52 0.030 350 5 60 Fair Example 15
[0137] The time before whitening of the polyamide-imide solution of
each of Examples 1 to 17 was equal to or longer than 5 minutes,
unlike that of the polyamide-imide solution or polyamide-amide acid
solution of each of Comparative Examples 1 to 15. Further, the time
before establishment of the tack-free state in the polyamide-imide
solution of each of Examples 1 to 17 was equal to or longer than 45
minutes, unlike that of the polyamide-imide solution or
polyamide-amide acid solution of each of Comparative Examples 1 to
15. This means that the polyamide-imide solution of each of
Examples 1 to 17 was excellent in coating applicability. Further,
the polyamide-imide film obtained had a very low thermal expansion
coefficient. In addition, as compared to the polyamide-imide film
obtained in Comparative Example 15, the polyamide-imide films
obtained in Examples 1 to 17 each had a lower linear thermal
expansion coefficient and a higher birefringence.
INDUSTRIAL APPLICABILITY
[0138] The polyamide-imide solution of the present invention has a
high dimensional stability and a high solubility in an organic
solvent, in addition to characteristics, such as heat resistance,
insulating property, and the like, that are inherent in
polyamide-imide. Further, the polyamide-imide solution of the
present invention is excellent in coating applicability. Therefore,
the polyamide-imide solution of the present invention can be
suitably employed in fields or products in which the
above-described characteristics are effective. Examples of such
fields or products are: optical materials such as a printed matter,
a color filter, a flexible display substrate, a TFT substrate, an
optical film, and the like; an image display device such as a
liquid crystal display device, an organic EL, and the electronic
paper; an electronic device material; and solar cells. Further, the
polyamide-imide solution of the present invention can also be
applied as a replacement material for a portion for which glass is
currently used.
* * * * *